Gear-wheel.



Patented Aug. 20, I90".

G. H. BOYD 81. T. D. WEST. GEAR WHEEL.

(Application filed July 26, 1899.) (No Model.)

I1E3,I-

QOWMJC' "Ta'irns Pattern nat on.-

GEORGE II. BOYD AND THOMAS D. "WEST, OF SHARPSVILLE, PENNSYL- VANIA.

G EAR WHEEL.

SPECIFICATION forming part of Letters Patent No. 680,688, dated August 20, 1901.

Application filed July 26, 1899.

To all whom it may concern:

Be it known that we, GEORGE H. BOYD and THOMAS D. WEST, residing at 'Sharpsville, Pennsylvania, have invented certain new and useful Improvements in Gear-Wheels; and We do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

Our invention relates to improvements in cast-metal gear-wheels and other cast-metal products having teeth.

The object of this invention is more especially to make a cast-metal gear which is reinforced within the toothed circumferential portion of the gear centrally between the faces of the teeth by metal plates cast in, so as to chill or harden the central portion of the teeth contiguous to the plates, and thereby produce a gear which is cheaper in construction and more durable than asteel gear.

In the accompanying drawings, Figure I is a perspective view of a gear-wheel embody ing our invention. Fig. II is an elevation of a portion of the gear. Fig. III is a section taken centrally through and radially of a tooth.

Referring to the drawings, a designates the hub, b the rim, and a radial arms, of a cast- 11011 gear-wheel, and the said parts constitute the body portion of the gear.

The rim 1) of the body portion is provided with teeth I), spaced equidistantly circumferentially of the gear. Within each tooth is a metal plate d, preferably of steel or wrought iron, and the said plate extends widthwise from side to side of the tooth and has its side edges preferably visible or exposed at the sides of the tooth. Each plate d extends lengthwise radially of the tooth of which it forms a part from within the outer end of the tooth to and beyond the tooths base into and radially of the body portion of the rim and is arranged centrally between the faces of the tooth. The plates d reinforce the teeth and are introduced by placing the plates in position Within the mold wherein the remainder Serial No. 725,126. (No model.)

of the gear is cast-that is, our improved cast-metal gear is made in the usual manner, except that the plates 61 are cast in the gear, being placed and held within the mold in any approved manner, so that the molten iron or metal poured or run into the mold shall flow around the plates and embed the said plates within the tooth-forming portions of the casting.

The presence of plates d,of steel or wroughtiron, within the mold in making a cast-iron gear chills and hardens the iron next adjacent to the said plates and renders the teeth exceedingly durable without materially affecting the teeth of the gear at and next to the faces of the teeth.

It is well known that two meshing gears seldom mesh with nice accuracy when new and that they wear themselves into proper mesh. The teeth of our improved gear are obviously not too hard upon or next to the surface to accommodate the shaping of the teeth in use, and the increase in hardness of the teeth toward the central or plate-embedding portions of the teeth causes the resistance to the wear upon the teeth to become greater with an increase of Wear upon the teeth.

What we claim is- 1. A cast-metal gear or toothed product hav ing metal plates which are embedded within the teeth and extend widthwise between the sides of the teeth and are arranged centrally between the faces of the teeth, the teeth being chilled or hardened contiguous to the said plates.

2. As a new article of manufacture, acastmetal gear or toothed product having its teeth chilled or hardened centrally between the faces of the teeth and decreasing in hardness toward the said faces.

Signed by us at Cleveland, Ohio, this 1st day of July, 1899.

GEORGE H. BOYD. THOMAS D. WEST. Witnesses:

O. H. Donna, A. H. PARRATT. 

